Wiring-knob.



No. 845,544. PATENTED FEB. 26, 1907.

.vention.

turn the cap on UNITED STATES WALDO O. GORDON, OF WINDSOR, VERMONT, ASSTGNOR TO THE ELECTRIC PATENT OFFICE.

0001) MANUFAcTURiNc COMPANY, or MAINE.

WIRING-*KNOBB Specification of Letters Patent.

Patented Feb. 26, 1907.

Application filed November 20, 1906. Serial No. 288,249.

To (LI/Z whom it may concern:

Be it known that I, WALDO C. GORDON, a citizen of the United States, and a resident of l Vindsor, in the county of lVindsor and State of Vermont, have invented a new and Improved Wirin -Knob, of which the folg lowing is a full, 0 ear, and exact description.

My invention relates to a wiring-knob or insulator for use in'gripping and supporting wires for conducting electricity.

The principal objects of the invention are to provide for more securely holding wires than has been the case with prior inventions of this character, and especially for so constructing the cap with which these insulators are usually provided that it will grip the wire equallyat all times independently of the position in which it may be placed on the base of the knob so long as it is centered with respect thereto.

Further objects of pear below. I

Reference is to be had to the accompany ing drawings, forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the figures.

Figure 1 is a sectional view on the line 1 1 of Fig. 3, showing a wiring-knob constructed in accordance with the principles of my in- Fig. 2 is a-central sectional view of the same at right angles to Fig. 1 plan of the face of the knob. Fig. 4 is a bottom plan of the cap. F g. 5 s a view similar to Fig. 1, showing additional features which can be employed; and Fig. 6 is a bottom plan the invention will apofthe cap shown in Fig. 5.

The wiring-knob, as. has previously been the case, comprises three elements-a base a, a cap 6, and a screw 0 or the like for holding the base and cap together. I have shown my invention as applied to that type of knobs in which the bolt is centrally located with respect to the knob and affords means for quickly centering the other two parts with respect to each other. Knobs have usually been constructed with one or more straight grooves through them, both in the body of the knob and in the cap. in order to cmploy these knobs, it is always necessary to the base until the grooves in the cap and base coincide with each other. I have-provided means for overcoming this difficulty. In the base I provide one or Fig. 3isa' [more grooves a, these grooves being providcd with corrugations a l In the form shown in Fig. 5 I have shown a projection or hump (1 in the groove a for l the purpose of forcing the wire upwardly at the center to engage the under surface of the cap b. The cap is flat and is provided with a circular depression I) for receiving a. projection a at the center of the base. Around this depression is an annular groove o the under side of which is preferably provided with radial corrugations 0?. ()n the outside of the groove 11 is a surface I), which is flat, except for a series of circular corrugations if. in this it will. be readily secn that the cap does not have to be turned to any particular position in order to provide for effectively gripping a wire. As shown in Fig. 1, the wire rests on the corrugated groove (1 and is secured by the corrugations If at the sides of the lower surface of the cap; but especially when the projection (L3 is employed the wire will be forced upwardly to the surface 12 and the corrugations I) will then assist in holding the wire. By placing two sets of corrugations on the cap, making an angle with each other, it will be seen that under all conditions the wire is securely hold in position.

l'laving thus described my invention, 1 claim as new and desire to secure by Letters Patent- 1. A wiring-knob or insulator comprising a base having at one side of its center a groove for a wire and a cap having a circular surface for engaging the wire, the said surface for engaging the wire lying within the circle of the base whereby said surface will operate upon that portion of the length of the wire lying in the groove of said base.

2. A wiring-knob or insulator comprising a base having a straight groove for a wire and a cap having a circular grooved surface for engaging the wire, said surface crossing the slraight groove at two points.

3. Awning-knob or insulator comprising a base having a corrugated groove across its upper surface and a cap having a flat surface crossing the groove at two points, said [lat surface being provided with circular corrugations.

4. Awiring-knobor insulatorcomprisinga base luiving a straight corrugated groove and a cap having a circular surface provided with a series of circular grooves adapted to rest on llie upper surface of llH base, said cap also being provided \\'Il li. a en'eular groove having I ailial corrugations and loeaie l within said eii'eulai' sul'l aoe.

5. A. airing-knob o1 insulator eonipi'isingr a base having a groove for a \\'l1'? and :1 'ap having a en'eulai SLHlilCl? for engaging ll'ie 5 wire, the saiil. suifaee for engaging tho Wire lying within the eirele of the base whereby saiil sui-l'aee will operate upon. that portion ol' the lengi h ol' the wire lying in the groove of 

